基于Autobank的湘江汛期某堤坝稳定性计算

Flood season stability calculation of a dam in Xiangjiang River using Autobank

堤坝稳定性一直是防汛难题,汛期高洪水位和汛退时水位陡降常导致堤坝渗透破坏和内外堤坡失稳,甚至引发溃堤。根据地质法获得汛期某已出险堤坝岩土物理力学参数,利用有限元法建模反演汛期稳定性,并通过汛期堤坝在不同水位状态下渗漏和变形失稳实测资料,对模拟计算采用参数进行校正,同时对设计加固堤坝的渗透和抗滑稳定性进行计算分析。结果表明:汛前原堤坝在设计水位、坝顶水位和水位陡降时会发生渗透破坏和堤坡失稳;加固堤坝在坝顶水位和水位陡降工况下内、外坡抗滑稳定,但在坝顶和设计水位时内、外坡脚会发生渗透破坏;调整加固方案后,抗渗和抗滑稳定性皆满足要求,调整后设计方案是可行的。

Dam stability has always been a challenge for the flood control,and high flood water level in flood season and steep drop of water level in flood recession often lead to seepage failure,instability of inner and outer slopes,and even dam breaches.The physical and mechanical parameters of the rock and soil of a damaged dam in flood season were obtained by the geological method,and the dam stability in flood season was inversed by the finite element method modeling.With the measured data of seepage and deformation instability of the dam in different water levels in flood season,the parameters used in the simulation calculation were calibrated,and the seepage and anti-sliding stability of the designed reinforced dam were calculated and analyzed.The results indicate that the seepage failure and slope instability will occur when the original dam is at designed water level,dam crest water level and steeply dropped water level before flood season.Whereas the inner and outer slopes of the reinforced dam will maintain stable when the reinforced dam is at dam crest water level and steeply dropped water level,but seepage failure will occur at the inner and outer dam feet at dam crest water level and designed water level.After adjusting the reinforcement scheme,the anti-seepage and anti-sliding stability can meet the requirements;therefore the adjusted design scheme is feasible.